FR3077373A1 - THERMAL MANAGEMENT CIRCUIT OF A HYBRID VEHICLE - Google Patents

Abstract

The present invention relates to a thermal management circuit (1) of a hybrid vehicle, said thermal management circuit (1) comprising: • a first circulation loop (A) of a refrigerant fluid adapted to operate in a mode of operation heat pump, • a second circulation loop (B) of a heat transfer fluid comprising: ° a first circulation branch (B1), and ° a second circulation branch (B2) arranged parallel to the first circulation branch (B1). ) and comprising: ▪ a bifluid heat exchanger (5), arranged jointly on the first circulation loop (A) and the second circulation branch (B 2), and ▪ an internal radiator (19), said thermal management circuit (1) being able to operate in a strict heating mode in which the heat transfer fluid flow Mw is regulated so that: Mw = (Ma.Cpa.eff. (Twri-Tai)) / (Cpw. (Twri -Tm ) Ma being the flow of air passing through the radiat internal air (19), Cpa the thermal capacity of the air, eff efficiency of the internal radiator (19), Twri the inlet temperature of the heat transfer fluid at the inlet of the internal radiator (19), Tai the temperature of the inlet air of the internal radiator (19), Cpw the thermal capacity of the coolant and Tm the temperature of the engine.

Description

® THERMAL MANAGEMENT CIRCUIT OF A HYBRID VEHICLE.

FR 3 077 373 - A1

@) The present invention relates to a thermal management circuit (1) of a hybrid vehicle, said thermal management circuit (1) comprising:

• a first circulation loop (A) of a coolant capable of operating in a heat pump operating mode, • a second circulation loop (B) of a heat transfer fluid comprising:

⁰ a first circulation branch (B1), and ⁰ a second circulation branch (B2) arranged parallel to the first circulation branch (B1) and comprising:

a two-fluid heat exchanger (5), arranged jointly on the first circulation loop (A) and the second circulation branch (B 2), and an internal radiator (19), said thermal management circuit (1) being capable of operate in a strict heating mode in which the heat transfer fluid flow Mw is regulated so that:

Mw = (Ma.Cpa.eff. (Twri - Tai)) / (Cpw. (Twri -Tm)

Ma being the air flow rate passing through the internal radiator (19), Cpa the thermal capacity of the air, eff the efficiency of the internal radiator (19), Twri the inlet temperature of the heat transfer fluid entering the internal radiator ( 19), Tai the temperature of the air entering the internal radiator (19), Cpw the thermal capacity of the heat transfer fluid and Tm the temperature of the heat engine.

^B B1

......

The invention relates to the field of motor vehicles and more particularly to a thermal management circuit for a hybrid motor vehicle.

In the case of so-called thermal motor vehicles, that is to say whose propulsion is provided by a heat engine, it is known to use the heat generated by the heat engine to heat the passenger compartment if necessary. However, hybrid motor vehicles have for their propulsion both a heat engine and one or more electric motors. When the engine is stopped, it is therefore not possible to use the heat it produces to heat the passenger compartment. In order to solve this problem, it is known to equip the vehicle with a heat pump which makes it possible to absorb heat energy in an external air flow and to restore it in an internal air flow in order to heat the passenger compartment.

In order to reduce costs and limit the energy consumption necessary to heat the passenger compartment, it is also known to use an indirect heat pump, that is to say comprising a first loop of refrigerant recovering the heat energy. in the external air flow and transferring it to a second loop of heat transfer fluid which releases it into the internal air flow via a two-fluid heat exchanger. The second heat transfer fluid loop is also connected to the engine cooling circuit. Document US2004200610 shows such an architecture of the thermal management circuit. It is thus possible to heat the passenger compartment via the heat pump when the heat engine is stopped and via the heat of the heat engine when it is running. However, this type of thermal management circuit has the disadvantage that when the heat engine is stopped, the first loop of coolant heats the coolant to a temperature which is higher than that of the heat engine stopped. Part of the heat generated by the first coolant loop will then be lost and absorbed by the cold engine.

One of the aims of the present invention is therefore to at least partially remedy the drawbacks of the prior art and to propose an improved thermal management circuit for a hybrid motor vehicle.

The present invention therefore relates to a thermal management circuit of a hybrid vehicle, said thermal management circuit comprising:

• a first circulation loop of a coolant capable of operating in a heat pump operating mode in which the coolant absorbs heat energy in an external air flow, • a second circulation loop of a heat transfer fluid comprising:

° a first circulation branch comprising, in the direction of circulation of the heat transfer fluid, a pump, an engine heat exchanger capable of exchanging with a heat engine and a first external radiator disposed in the external air flow, and ° a second branch circulation arranged parallel to the first circulation branch so as to bypass at least the first external radiator, said second circulation branch comprising in the direction of circulation of the heat transfer fluid:

a two-fluid heat exchanger, arranged jointly on the first circulation loop and the second circulation branch and capable of allowing exchanges of heat energy between the refrigerant and the heat transfer fluid, and an internal radiator arranged in an air flow internal, downstream of the dual-fluid heat exchanger, said thermal management circuit being capable of operating in a strict mode of heating the passenger compartment in which the first circulation loop is in heat pump mode and in which at the outlet of the pump, the heat transfer fluid bypasses the external radiator and passes into the second circulation branch, characterized in that in this strict heating mode of the passenger compartment, the flow of heat transfer fluid Mw is regulated so that:

Mw = (Ma.Cpa.eff. (Twri - Tai)) / (Cpw. (Twri -Tm)

Ma being the air flow rate passing through the internal radiator, Cpa the thermal capacity of the air, eff the efficiency of the internal radiator, Twri the inlet temperature of the heat transfer fluid entering the internal radiator, Tai the temperature of the air entering the internal radiator, Cpw the thermal capacity of the heat transfer fluid and Tm the temperature of the heat engine.

According to one aspect of the invention, during a cold start, the flow of heat transfer fluid Mw is regulated so that:

Mw = (Ma.Cpa.eff) / Cpw

According to another aspect of the invention, the first circulation loop comprises in the direction of circulation of the refrigerant:

• a compressor, • the two-fluid heat exchanger, • a first expansion device, and • a second external radiator.

According to another aspect of the invention, the first circulation loop of a coolant is able to operate in a cooling operating mode in which the coolant absorbs heat energy in the internal air flow.

According to another aspect of the invention, the first circulation loop further comprises:

• a second expansion device, arranged downstream of the second external radiator, • an evaporator, arranged downstream of the second expansion device, and • a bypass pipe (Al) of the two-fluid heat exchanger.

According to another aspect of the invention, the second circulation branch comprises:

° a first connection point with the first circulation branch arranged between the pump and the engine heat exchanger, and ° a second connection point with the first circulation branch arranged between the first external radiator and the pump.

According to another aspect of the invention, the second circulation loop includes a third circulation branch comprising, in the direction of circulation of the heat transfer fluid:

° a first connection point arranged between the engine heat exchanger and the first external radiator, and ° a second connection point arranged between the first connection point of the second circulation branch and the dual-fluid heat exchanger.

According to another aspect of the invention, the thermal management circuit is configured to operate in a mode of preheating of the heat engine and heating of the passenger compartment in which the first circulation loop is in heat pump mode and in which at the outlet of the pump, • part of the heat transfer fluid passes into the second circulation branch, the heat transfer fluid exchanging heat energy with the internal air flow at the internal radiator, • another part of the heat transfer fluid passes through the engine heat exchanger and returns to the second circulation branch via the third circulation branch.

According to another aspect of the invention, the thermal management circuit is configured to operate in a preheating mode of the heat engine in which the first circulation loop is in heat pump mode and in which, at the outlet of the pump, • part of the heat transfer fluid passes through the second circulation branch, the heat transfer fluid passing through the internal radiator without exchanging heat energy with the internal air flow, • another part of the heat transfer fluid passes through the heat exchanger engine and returns to the second circulation branch via the third circulation branch.

According to another aspect of the invention, the thermal management circuit is configured to operate in a mode of cooling the heat engine and heating the passenger compartment in which the first circulation loop does not transfer heat energy to the second circulation loop and in which, at the outlet of the pump, the heat transfer fluid passes through the engine heat exchanger, at the outlet from the engine heat exchanger, • part of the heat transfer fluid passes through the third circulation branch to join the second circulation branch at the level of which the heat transfer fluid exchanges heat energy with the internal air flow by passing through the internal radiator before returning to the pump, • another part of the heat transfer fluid joins the first external radiator before returning to the pump.

Other characteristics and advantages of the invention will appear more clearly on reading the following description, given by way of illustrative and nonlimiting example, and of the appended drawings among which:

• Figure 1 shows a schematic representation of a thermal management circuit according to a first embodiment, • Figure 2 shows a schematic representation of a thermal management circuit according to a second embodiment, • Figure 3 shows a schematic representation of the thermal management circuit of FIG. 1 according to a first operating mode, • FIG. 4 shows a schematic representation of the thermal management circuit of FIG. 1 according to a second operating mode, • FIG. 5 shows a schematic representation of the thermal management circuit of Figure 1 according to a third mode of operation, • Figure 6 shows a schematic representation of the thermal management circuit of Figure 1 according to a fourth mode of operation.

In the various figures, identical elements have the same reference numbers.

The following embodiments are examples. Although the description refers to one or more embodiments, this does not necessarily mean that each reference relates to the same embodiment, or that the characteristics apply only to a single embodiment. Simple features of different embodiments can also be combined and / or interchanged to provide other embodiments.

In the present description, it is possible to index certain elements or parameters, for example first element or second element as well as first parameter and second parameter or even first criterion and second criterion etc. In this case, it is a simple indexing to differentiate and name elements or parameters or criteria close, but not identical. This indexing does not imply a priority of an element, parameter or criterion over another and one can easily interchange such names without departing from the scope of this description. This indexing does not imply an order in time for example to assess this or that criterion.

In the present description, the term "placed upstream" means that one element is placed before another with respect to the direction of circulation of a fluid. Conversely, by "placed downstream" is meant that one element is placed after another with respect to the direction of circulation of the fluid.

Figure 1 shows a thermal management circuit 1 of a hybrid vehicle. This thermal management circuit 1 comprises a first circulation loop A of a refrigerant fluid as well as a second circulation loop B of a heat transfer fluid. These two circulation loops A and B are in thermal connection with each other so that exchanges of heat energy can take place between the refrigerant fluid of the first circulation loop A and the heat transfer fluid of the second loop for circulation B. For this, a two-fluid heat exchanger 5 is arranged jointly on the first A circulation loop and the second circulation loop B. This two-fluid heat exchanger 5 is able to allow the exchange of heat energy between the fluid refrigerant and heat transfer fluid.

The second circulation loop B of heat transfer fluid comprises in particular:

A first circulation branch B1 comprising, in the direction of circulation of the heat transfer fluid, a pump 13, an engine heat exchanger 15 capable of exchanging with a heat engine and a first external radiator 8 disposed in the external air flow 100, and ° a second circulation branch B2 arranged parallel to the first circulation branch B1 so as to bypass at least the first external radiator 8.

This second circulation branch B2 comprises in the direction of circulation of the heat transfer fluid:

the two-fluid heat exchanger 5, and an internal radiator 19 disposed in an internal air flow 200, downstream of the two-fluid heat exchanger 5.

More specifically, the second branch of circulation B2 comprises:

° a first connection point 31 with the first circulation branch B1 disposed between the pump 13 and the engine heat exchanger 15, and ° a second connection point 32 with the first circulation branch B1 disposed between the first external radiator 8 and pump 13.

The second circulation loop B may also include a third circulation branch B3 comprising, in the direction of circulation of the heat transfer fluid:

° a first connection point 41 disposed between the engine heat exchanger 15 and the first external radiator 8, and ° a second connection point 42 disposed between the first connection point 31 of the second circulation branch B2 and the exchanger dual fluid heat 5.

As shown in Figure 1, the second circulation loop B can also include:

• a first stop valve 21 arranged on the third circulation branch B3, and • a second stop valve 22 arranged on the first circulation branch B1 downstream of the first external radiator 8, between said first external radiator 8 and the second connection point 32 of the second circulation branch B2, and • a third stop valve 23 disposed between the first connection point 31 of the second circulation branch B2 and the second connection point 42 of the third circulation branch B3.

These first 21, second 22 and third 23 stop valves make it possible to define the circulation of the heat transfer fluid and thus control in which elements said heat transfer fluid circulates.

It is of course quite possible to imagine other means for controlling the circulation of the heat transfer fluid in the second circulation loop B without departing from the scope of the invention.

As for it, the first circulation loop A is more particularly capable of operating in a heat pump operating mode. In this heat pump mode, the refrigerant absorbs heat energy in an outside air flow 100, in order to transfer it to the heat transfer fluid of the second circulation loop B.

As illustrated in FIG. 1, for this, the first circulation loop A can comprise in the direction of circulation of the refrigerant:

• a compressor 3, • the dual-fluid heat exchanger 5, • a first expansion device 7, and • a second external radiator 9 disposed in the outside air flow 100.

The first circulation loop A can also comprise upstream of the compressor 3 an accumulator 11 of the refrigerant fluid.

In heat pump mode, the compressor 3 compresses the refrigerant and the latter then passes into the two-fluid heat exchanger 5. As it passes through the two-fluid heat exchanger, 5, the refrigerant gives up heat energy to the heat transfer fluid of the second circulation loop B. The refrigerant then passes through the first expansion device 7 and undergoes a pressure loss. The refrigerant then passes into the second external radiator 9 at which it recovers heat energy from the outside air flow 100 before returning to the compressor 3.

The first circulation loop A can also be a circulation loop capable of operating in a cooling operating mode in which the refrigerant absorbs heat energy in the internal air flow 200.

FIG. 2 shows an example of the first circulation loop A which is able to operate in this cooling mode. For this, the first circulation loop A additionally comprises in the direction of circulation of the coolant:

• a second expansion device 70, arranged downstream of the second external radiator 9, • an evaporator 20, arranged downstream of the second expansion device 70, and • a bypass pipe Al of the two-fluid heat exchanger 5.

In order to bypass the two-fluid heat exchanger 5, the bypass line Al comprises:

• a first connection point 51 disposed downstream of the compressor 3, between said compressor 3 and the dual-fluid heat exchanger 5, and • a second connection point 52 disposed downstream of the dual-fluid heat exchanger 5.

The second connection point of the bypass pipe A1 can, as illustrated in FIG. 2, be arranged between the two-fluid heat exchanger 5 and the first expansion device 7. In this case, said first expansion device 7 is capable of being traversed by the refrigerant without loss of pressure.

An alternative not shown is that the second connection point 51 of the bypass pipe A1 is placed downstream of the first expansion device 7, between said expansion device 7 and the second external radiator 9.

The bypass pipe A1 may also include a stop valve 24 allowing the passage or not of the refrigerant in order to define its path and whether or not it crosses the two-fluid heat exchanger 5. It is of course possible to imagine , without departing from the scope of the invention, a system for controlling the path of the different refrigerant, for example by means of a three-way valve at the first connection point 51.

In cooling mode, the refrigerant is compressed at the compressor 3 and then passes into the second external radiator 9 without loss of pressure via the bypass line A1. The refrigerant loses heat energy in the air flow outside 100 through the second external radiator 9. The refrigerant then passes into the second expansion device 70 at which it undergoes a pressure loss. The refrigerant then passes through the evaporator 20 at the level of which it recovers heat energy by cooling the internal air flow 200. The refrigerant then joins the compressor 3.

Still for the bypass line A1 of FIG. 2, in heat pump mode, the compressor 3 compresses the refrigerant fluid and the latter then passes into the two-fluid heat exchanger 5 without passing through the bypass line Al. passage through the two-fluid heat exchanger 5, the refrigerant transfers heat energy to the heat transfer fluid of the second circulation loop B. The refrigerant then passes through the first expansion device 7 and undergoes a pressure loss . The refrigerant then passes into the second external radiator 9 at which it recovers heat energy from the external air flow 100. The refrigerant then passes into the second expansion device 70 which it passes through without loss of pressure. The refrigerant then passes through the evaporator 20 which it passes through without exchanging heat energy with the internal air flow 200. For this, the internal air flow can for example be blocked by a flap (not shown) so as not to pass through the evaporator 20. The refrigerant then joins the compressor 3.

When the first circulation loop A is in heat pump mode, the thermal management circuit 1 is in particular capable of operating according to different operating modes illustrated in FIGS. 3 to 6.

1. strict heating mode of the passenger compartment

FIG. 3 shows a first mode of operation known as the strict heating mode of the passenger compartment in which, at the outlet of the pump 13, the heat transfer fluid bypasses the external radiator 8 and passes into the second circulation branch B2. In this strict mode of heating the passenger compartment, the heat engine is stopped.

The first circulation loop A is in heat pump mode and the heat energy recovered in the external air flow 100 is entirely devoted to heating the internal air flow 200.

In the particular example of FIG. 3, the heat transfer fluid in the second circulation loop B passes successively through the pump 13 and the two-fluid heat exchanger 5 at the level of which the heat transfer fluid recovers heat energy from the fluid refrigerant. The heat transfer fluid then circulates in the internal radiator 19 at which it heats the internal air flow 200 by yielding heat energy to it.

The heat transfer fluid does not pass through the engine heat exchanger 15 or into the third circulation branch B 3 because the first 21 and second 22 stop valves are closed. The third stop valve 23 is open.

So that this operating mode does not impact the thermal management of the heat engine when the latter is in operation while allowing a target temperature of the internal air flow 200 to be reached in order to heat the passenger compartment, the flow of heat-transfer fluid Mw is regulated so that:

Mw = (Ma.Cpa.eff. (Twri - Tai)) / (Cpw. (Twri -Tm))

Mw corresponds to the flow of heat transfer fluid circulating in the second circulation branch B2, expressed in Kg / h. This flow of heat transfer fluid Mw can in particular be controlled by varying the speed of the pump 13.

Ma corresponds to the air flow rate passing through the internal radiator 19, expressed in Kg / h. This air flow Ma can be determined by means of a sensor arranged in the direction of the internal air flow 200 upstream of the internal radiator 19 or alternatively as a function of the speed of a fan generating said air flow internal 200.

Cpa corresponds to the thermal capacity of the air, expressed in J / Kg / K.

eff corresponds to the efficiency of the internal radiator 19,

Twri corresponds to the temperature of the heat transfer fluid at the inlet of the internal radiator 19, expressed in K. This Twri temperature can be measured by a temperature sensor disposed in the direction of the coolant upstream from the internal radiator 19.

Tai corresponds to the temperature of the air entering the internal radiator 19, expressed in K. This temperature Tai can be measured by a temperature sensor disposed in the direction of the internal air flow 200 upstream of the internal radiator 19. This temperature can also be determined as a function of the outside temperature of the vehicle measured by a sensor if the internal air flow 200 is outside air or as a function of the inside temperature of the vehicle measured by a sensor if the air flow internal 200 is recirculated air.

Cpw corresponds to the thermal capacity of the heat transfer fluid, expressed in J / Kg / K.

Tm corresponds to the temperature of the heat engine, expressed in K. This temperature Tm is in particular determined by a sensor placed at the level of the heat engine.

In fact, the heating capacity Hc of the internal radiator 19, expressed in W or J / s is defined according to two formulas:

formula 1): Hc = Mcpw. (Twri - Twro)

Twro corresponds to the temperature of the heat transfer fluid at the outlet of the internal radiator 19, expressed in K.

Mcpw = Mw.Cpw. 1/3600, Mcpw being expressed in W / K.

So Hc = Mw.Cpw. 1/3600. (Twri - Twro) and Mw = Hc / (Cpw. 1/3600. (Twri - Twro)) formula 2): Hc = Mcpa. (Tao - Tai)

Tao corresponds to the temperature of the air leaving the internal radiator 19, expressed in K.

Mcpa = Ma.Cpa. 1/3600, Mcpa being expressed in W / K.

According to a third formula 3): (Tao - Tai) = eff. (Twri - Tai)

Thus formula 2) can also be written:

Hc = Ma.Cpa. 1 / 3600.eff. (Twri - Tai)

By combining formulas 1) and 2) we therefore obtain:

Mw = (Ma.Cpa. 1 / 3600.eff. (Twri - Tai)) / (Cpw.l / 3600. (Twri - Twro)) simplified in Mw = (Ma.Cpa.eff. (Twri - Tai)) / (Cpw. (Twri - Twro))

So that the temperature of the heat transfer fluid leaving the internal radiator 19 does not impact the thermal management of the heat engine, it is thus necessary that Twro = Tm.

Thus, Mw = (Ma.Cpa.eff. (Twri - Tai)) / (Cpw. (Twri -Tm))

It is even also possible to simplify this equation, in particular by using a heat transfer fluid such as glycol water which has a thermal capacity Cpw close to 3600 J / Kg / K.

In this case, formula 1) can be written:

Mw = Hc / (Twri - Twro)

And so we get in the end in this scenario:

Mw = Mcpa.eff. (Twri - Tai)) / (Twri -Tm)

In the particular case where the hybrid motor vehicle operates a cold start, the flow of heat transfer fluid Mw can be more particularly regulated until the heat engine reaches an optimal operating temperature range so that:

Mw = (Ma.Cpa.eff) / Cpw

In fact, during a cold start, the engine temperature Tm is equal to the outside air temperature, therefore at Tai.

So,

Mw = (Ma.Cpa.eff. (Twri - Tai)) / (Cpw. (Twri -Tai)) = (Ma.Cpa.eff) / Cpw

2. mode for preheating the engine and heating the passenger compartment

The thermal management circuit 1 can also operate in a mode for preheating the heat engine and heating the passenger compartment, illustrated in FIG. 4.

In this operating mode, the first circulation loop A is in heat pump mode. The heat engine is running, but is at a temperature below its optimal operating temperature. This operating mode allows this optimal operating temperature to be reached more quickly while heating the passenger compartment.

At the second circulation loop B, at the outlet of the pump 13, part of the heat transfer fluid passes through the second circulation branch B2. The heat transfer fluid exchanges heat energy with the internal air flow 200 at the internal radiator 19 in order to heat the internal air flow 200 and therefore the passenger compartment.

Another part of the heat transfer fluid passes through the engine heat exchanger 15 and returns to the second circulation branch B2 via the third circulation branch B3. Part of the heat energy recovered from the heat pump of the first circulation loop A is therefore used to heat the heat engine via the engine heat exchanger 15.

In the example in Figure 4, so that the heat transfer fluid follows this path, the first stop valve 21 and the third stop valve 23 are open. The second stop valve 22 is closed.

3. heat engine preheating mode

The thermal management circuit 1 can also operate in a preheating mode of the thermal engine, illustrated in FIG. 5.

In this operating mode, the first circulation loop A is in heat pump mode. The heat engine is running, but is at a temperature below its optimal operating temperature. This operating mode enables this optimal operating temperature to be reached more quickly.

At the second circulation loop B, at the outlet of the pump 13, part of the heat transfer fluid passes through the second circulation branch B2. The heat transfer fluid passes through the internal radiator 19, however, without exchanging heat energy with the internal air flow 200. This is possible for example by blocking the internal air flow 200 by means of a flap so that it does not pass through not the internal radiator 19.

Another part of the heat transfer fluid passes through the engine heat exchanger 15 and returns to the second circulation branch B2 via the third circulation branch B3. The heat energy recovered from the heat pump of the first circulation loop A is therefore used to heat the heat engine via the engine heat exchanger 15.

In the example in FIG. 5, so that the heat transfer fluid follows this path, the first stop valve 21 and the third stop valve 23 are open. The second stop valve 22 is closed.

4. method of cooling the engine and heating the passenger compartment

The thermal management circuit 1 can also operate in a mode of cooling the thermal engine and heating the passenger compartment, illustrated in FIG.

6.

In this operating mode, the first circulation loop A does not transfer heat energy to the second circulation loop B, for example because said first circulation loop A is stopped or the refrigerant does not pass through not the two-fluid heat exchanger 5. The heat engine is running and must be cooled in order to be kept close to its optimum operating temperature.

At the second circulation loop B, at the outlet of the pump 13 the heat transfer fluid passes through the engine heat exchanger 15 and at the outlet of the latter, part of the heat transfer fluid passes through the third circulation branch B3 to reach the second branch of circulation B2. The heat transfer fluid then passes through the dual fluid heat exchanger 5 without exchanging heat energy and then passes through the internal radiator 19. The heat transfer fluid exchanges heat energy with the internal air flow 200 by passing through the internal radiator 19 before return to pump 13.

Another part of the heat transfer fluid leaving the engine heat exchanger 15 joins the first external radiator 8 at which it transfers heat energy to the outside air flow 100 before returning to the pump 13.

The two heat transfer fluid flows meet upstream of the pump 13 at the second connection point 32 of the second circulation branch B2.

The heat energy released by the heat engine is thus evacuated in the external air flow 100 at the first external radiator 8, but also in the internal air flow 200 at the internal radiator 19 in order to heat the passenger compartment. .

In the example of FIG. 6, so that the heat transfer fluid follows this path, the first 5 stop valve 21 and the second stop valve 22 are open. The third stop valve 23 is closed.

Thus, it is clear that the thermal management circuit 1 according to the invention by its management mode makes it possible to have little or no impact on the thermal management of the heat engine. In addition, by its architecture, the thermal management circuit 1 allows operation according to different modes of operation.

Claims (10)

1. Thermal management circuit (1) of a hybrid vehicle, said thermal management circuit (1) comprising: • a first circulation loop (A) of a coolant capable of operating in a heat pump operating mode in which the coolant absorbs heat energy in an outside air flow (100), • a second circulation loop (B) of a heat transfer fluid comprising: ° a first circulation branch (B1) comprising in the direction of circulation of the heat transfer fluid, a pump (13), an engine heat exchanger (15) capable of exchanging with a heat engine and a first external radiator (8) disposed in the outside air flow (100), and ° a second circulation branch (B2) arranged parallel to the first circulation branch (Bl) so as to bypass at least the first external radiator (8), said second circulation branch (B2) comprising in the direction of circulation of the heat transfer fluid: a two-fluid heat exchanger (5), arranged jointly on the first circulation loop (A) and the second circulation branch (B2) and capable of allowing exchanges of heat energy between the refrigerant and the heat transfer fluid, and a internal radiator (19) disposed in an internal air flow (200), downstream of the dual-fluid heat exchanger (5), said thermal management circuit (1) being able to operate in a strict heating mode of l cabin in which the first circulation loop (A) is in heat pump mode and in which, at the outlet of the pump (13), the heat transfer fluid bypasses the external radiator (8) and passes into the second circulation branch (B 2), characterized in that in this strict heating mode of the passenger compartment, the flow of heat transfer fluid Mw is regulated so that: Mw = (Ma.Cpa.eff. (Twri - Tai)) / (Cpw. (Twri -Tm) Ma being the air flow rate passing through the internal radiator (19), Cpa the thermal capacity of the air, eff the efficiency of the internal radiator (19), Twri the inlet temperature of the heat transfer fluid entering the internal radiator ( 19), Tai the temperature of the air entering the internal radiator (19), Cpw the thermal capacity of the heat transfer fluid and Tm the temperature of the heat engine. 2. Thermal management circuit (1) according to claim 1, characterized in that during a cold start, the flow of heat transfer fluid Mw is regulated so that: Mw = (Ma.Cpa.eff) / Cpw 3. Thermal management circuit (1) according to one of the preceding claims, characterized in that the first circulation loop (A) comprises in the direction of circulation of the refrigerant: • a compressor (3), • the two-fluid heat exchanger (5), • a first expansion device (7), and • a second external radiator (9). 4. Thermal management circuit (1) according to the preceding claim, characterized in that the first circulation loop (A) of a refrigerant is capable of operating in a cooling operating mode in which the refrigerant absorbs l heat energy in the internal air flow (200). 5. Thermal management circuit (1) according to the preceding claim, characterized in that the first circulation loop (A) further comprises: • a second expansion device (70), arranged downstream of the second external radiator (9), • an evaporator (20), disposed downstream of the second expansion device (70), and • a bypass pipe (Al) of the two-fluid heat exchanger (5). 6. Thermal management circuit (1) according to one of the preceding claims, characterized in that the second circulation branch (B2) comprises: ° a first connection point (31) with the first circulation branch (Bl) disposed between the pump (13) and the engine heat exchanger (15), and ° a second connection point (32) with the first branch circulation (Bl) disposed between the first external radiator (8) and the pump (13). 7. Thermal management circuit (1) according to the preceding claim, characterized in that the second circulation loop (B) comprises a third circulation branch (B 3) comprising in the direction of circulation of the heat transfer fluid: ° a first connection point (41) disposed between the engine heat exchanger (15) and the first external radiator (8), and ° a second connection point (42) disposed between the first connection point (31) of the second circulation branch (B2) and the two-fluid heat exchanger (5). 8. A thermal management circuit (1) according to claim 7, characterized in that it is configured to operate in a mode of preheating of the heat engine and heating of the passenger compartment in which the first circulation loop (A ) is in heat pump mode and in which, at the outlet of the pump (13), • part of the heat transfer fluid passes through the second circulation branch (B2), the heat transfer fluid exchanging heat energy with the flow of internal air (200) at the internal radiator (19), • another part of the heat transfer fluid passes through the engine heat exchanger (15) and returns to the second circulation branch (B2) via the third circulation branch ( B3). 9. thermal management circuit (1) according to claim 7, characterized in that it is configured to operate in a preheating mode of the heat engine in which the first circulation loop (A) is in heat pump mode and in which, at the outlet of the pump (13), • part of the heat transfer fluid passes through the second circulation branch (B2), the heat transfer fluid passing through the internal radiator (19) without exchanging heat energy with the flow d internal air (200), • another part of the heat transfer fluid passes through the engine heat exchanger (15) and returns to the second circulation branch (B2) via the third circulation branch (B3). 10. Thermal management circuit (1) according to one of claims 6 or 7, characterized in that it is configured to operate in a mode of cooling of the thermal engine and heating of the passenger compartment in which the first loop of circulation (A) does not transfer heat energy to the second circulation loop (B) and in which at the outlet of the pump (13) the heat transfer fluid passes through the engine heat exchanger (15), at the outlet of the 'engine heat exchanger (15), • part of the heat transfer fluid passes through the third circulation branch (B3) to join the second circulation branch (B2) at which the heat transfer fluid exchanges heat energy with the internal air flow (200) passing through the internal radiator (19) before returning to the pump (13),